existing alone or consisting of one entity or part or aspect or individual; "upon the hill stood a single tower"; "had but a single thought which was to escape"; "a single survivor"; "a single serving"; "a single lens"; "a single thickness"
not married or related to the unmarried state; "unmarried men and women"; "unmarried life"; "sex and the single girl"; "single parenthood"; "are you married or single?"
not divided among or brought to bear on more than one object or objective; "judging a contest with a single eye"; "a single devotion to duty"; "undivided affection"; "gained their exclusive attention"